Cement mixer and bone filler device

ABSTRACT

An apparatus and method for mixing and dispensing bone cement is provided. The apparatus includes a mixing vessel for mixing bone cement attached to a syringe body. The syringe body having a lumen that is connected to the mixing vessel by a passageway between the mixing vessel and the lumen of the syringe body. A separator is provided between the mixing vessel and the syringe body and includes an orifice therein so that when the opening in the separator is misaligned with the lumen the passageway is blocked and when aligned the passageway is continuous with the lumen so that bone cement can pass into the syringe body. A plunger is provided and is slideably movable along the longitudinal axis of the syringe body so as to advance the bone cement out of the distal end of the syringe.

TECHNICAL FIELD

The present invention relates to devices and methods for mixing curablematerials for use with stabilizing bone structures. More particularly,it relates to devices, systems and methods for mixing the componentsthat form the curable materials.

BACKGROUND

Vertebral compression fracture (VCF) can occur when a vertebral body istoo weak to support a load and the spine collapses. A VCF may cause thespine to shorten, leading to spinal deformities and altering spinalbiomechanics. Collapse may result in thoracic and lumbar spinaldeformity and is often seen in elderly people. The spinal deformity,commonly known as a Dowager's Hump, is also referred to as kyphosis.Several causes can lead to a VCF, including osteoporosis, cancer or atraumatic incident, such as a fall or car accident.

A treatment for a VCF can involve injecting a material into vertebra,either at low or high pressure. Optionally, a surgical balloon can firstbe inserted into a vertebra and expanded to restore a collapsed vertebrato its original shape. A material can then be inserted into the restoredvertebra, which, upon hardening, can maintain the original shape of thevertebra. The technique of inserting a material into a cavity, such as acollapsed vertebra, can also be used to treat other medical conditions,for example, in knee or hand joints.

Surgeons commonly use bone cement in order to fill voids in bone. It isdesirable to use bone cement, such as an adhesive bone cement, to holdsmall bone fragments in place to allow for healing, when methods such astraditional plate and screw methods of reattachment are not feasible.Only a small amount of bone cement may be required to fill small gapsbetween the bone fragments in order to glue the fragments together. Forexample, volumes of cement under one cubic centimeter may be used. Insuch applications, the cement material may be delivered to the repairsite through a delivery system, such as a syringe having a cannulatedneedle.

The bone cement may be a mixture of different ingredients, and, beforeapplying the bone cement to a repair site, the cement may be prepared bymixing it in a bowl with a pestle. Prepared bone cements can havevarious viscosities, and some may have quite a high viscosity, with aconsistency like a tacky paste. For example, typical adhesive bonecement may have a viscosity greater than 80 Pascal-seconds. The preparedbone cement can be transferred to the syringe through the opening in theproximal end of the syringe, which is made accessible by removing theplunger from the syringe.

The prepared cement material can be difficult to pour into the proximalend of an application syringe, especially when it has a high viscosity.Additionally, the opening at the proximal end of the syringe may bequite small, thus making the pouring of the bone cement into the syringeeven more difficult. The pouring of the bone cement into the proximalend of the syringe can also be time consuming, which can be problematicwhen the curing time for the cement is relatively short. Furthermore,the material that is poured into the proximal end of the syringe candevelop air pockets along the syringe barrel. Air pockets candetrimentally cause pressure spikes during injection of the cement.These pressure increases can cause filter pressing, where the liquidportion of the cement separates from the powder portion. This can resultin the liquid being squeezed out of the syringe, leaving behind a densemass of powder, which can jam the syringe.

SUMMARY

This application relates to an apparatus for mixing and delivering bonecement and a method for filling a cavity in a patient's body with bonecement. The apparatus includes a mixing vessel for mixing the first andsecond materials to prepare the bone cement for delivery. A syringe bodyis attached to the mixing vessel. The syringe body defines a lumen and alongitudinal axis extending from a proximal end to an oppositelydisposed distal end of the syringe body. Each of the proximal and distalends having an opening therein. The openings in the syringe body areafignable with the orifice in the mixing vessel so as to provide apassageway between the mixing vessel and the lumen of the syringe body.A separator is provided between the mixing vessel and the proximal endof the syringe body. The separator includes an orifice therein. Theseparator is configured to slide between a first position wherein theorifice of the separator substantially aligns with the orifice in themixing vessel and the passageway to a second position wherein theopening in the separator is misaligned so as to block the passagewaybetween said mixing vessel and the passageway. When the separator is inthe first position, the bone cement is transferred from the mixingvessel through the lumen to a dispensing structure. A plunger isprovided and is configured to fit into the opening in the passagewaybetween said mixing vessel and the lumen of the syringe body. Theplunger is slideably movable along the central axis toward the distalend of the syringe body to facilitate movement of the bone cement intothe dispensing structure.

A kit including one or all of the components of the bone cement mixingapparatus is provide, such as for example, a disposable, peel-pack,pre-packed sterile devices. The kit can also be provided in a sterilizedor in the alternative be provided in a sterilizable packaging. The kitincludes, at least one of the following: syringe body, mixing vessel,separator, plunger, base and dispensing structures. The syringes anddispensing structures can be of various sizes, gauges and typesdepending on the particular application. One or all of the components ofthe bone cement mixing apparatus may be reusable and sterilizable. Thebone mixing apparatus may be configured as a kit with multiple sized andconfigured components.

The method of using the apparatus includes attaching a mixing vessel toa syringe body including a lumen and defining a passageway. A separatoris positioned in a second position, where its orifice is not alignedwith the orifice of the mixing vessel. A base can be attached to providean easier gripping surface for holding the apparatus. Bone cementmaterials are place inside mixing vessel and are mixed thoroughly with aspatula. Once bone cement materials are thoroughly mixed, the separatoris shifted to the first position where its orifice is aligned with theorifice of the mixing vessel and then passageway. The spatula is used topush and guide the bone cement mixture into the syringe body. A plungeris placed into the passageway of the syringe body through the orificesof the separator and the mixing vessel and is pushed towards the distalend of the syringe body. The apparatus is flipped over so that thehandle of the plunger rests on table or other surface. If a base wasattached, it can now be removed. A dispensing structure is attached thesyringe body. A force can be applied to flanges to push the bone cementmaterial into the dispensing structure. A plurality of dispensingstructures can be filled one after another as needed for the particularuse.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more readily apparent from thespecific description accompanied by the following drawings, in which:

FIG. 1 is a perspective view of one particular embodiment of a system inaccordance with the principles of the present disclosure;

FIG. 2 is a perspective view of components system shown in FIG. 1 wherethe separator is in a second position;

FIG. 3 is a perspective view of components of the system shown in FIG. 1where the separator is in a first position;

FIG. 4 is a perspective view of components of the system shown in FIG. 1including a spatula;

FIG. 5 is a perspective view of components of the system shown in FIG. 1turned upside down and including the plunger;

FIG. 6 is a perspective view of components of the system shown in FIG.5;

FIG. 7 is a perspective view of components of the system shown in FIG. 1including a dispensing structure;

Like reference numerals indicate similar parts throughout the figures.

DETAILED DESCRIPTION

An apparatus and method is described for injecting a material into acavity in a patient's body. For illustrative purposes, the apparatus andmethod shall be described in the context of injecting a bone fillingcement into a vertebra of a patient to treat kyphosis, although theapparatus and methods can be used to treat other conditions.

The present disclosure may be understood more readily by reference tothe following detailed description of the disclosure taken in connectionwith the accompanying drawing figures, which form a part of thisdisclosure. It is to be understood that this disclosure is not limitedto the specific devices, methods, conditions or parameters describedand/or shown herein, and that the terminology used herein is for thepurpose of describing particular embodiments by way of example only andis not intended to be limiting of the claimed disclosure. Also, as usedin the specification and including the appended claims, the singularforms “a,” “an,” and “the” include the plural, and reference to aparticular numerical value includes at least that particular value,unless the context clearly dictates otherwise. Ranges may be expressedherein as from “about” or “approximately” one particular value and/or to“about” or “approximately” another particular value. When such a rangeis expressed, another embodiment includes from the one particular valueand/or to the other particular value. Similarly, when values areexpressed as approximations, by use of the antecedent “about,” it willbe understood that the particular value forms another embodiment. It isalso understood that all spatial references, such as, for example,horizontal, vertical, top, upper, lower, bottom, left and right, are forillustrative purposes only and can be varied within the scope of thedisclosure. For example, the references “upper” and “lower” are relativeand used only in the context to the other, and are not necessarily“superior” and “inferior”.

Further, as used in the specification and including the appended claims,“treating” or “treatment” of a disease or condition refers to performinga procedure that may include administering one or more drugs to apatient (human, normal or otherwise or other mammal), in an effort toalleviate signs or symptoms of the disease or condition. Alleviation canoccur prior to signs or symptoms of the disease or condition appearing,as well as after their appearance. Thus, treating or treatment includespreventing or prevention of disease or undesirable condition (e.g.,preventing the disease from occurring in a patient, who may bepredisposed to the disease but has not yet been diagnosed as having it).In addition, treating or treatment does not require complete alleviationof signs or symptoms, does not require a cure, and specifically includesprocedures that have only a marginal effect on the patient. Treatmentcan include inhibiting the disease, e.g., arresting its development, orrelieving the disease, e.g., causing regression of the disease. Forexample, treatment can include reducing acute or chronic inflammation;alleviating pain and mitigating and inducing re-growth of new ligament,bone and other tissues; as an adjunct in surgery; and/or any repairprocedure. Also, as used in the specification and including the appendedclaims, the term “tissue” includes soft tissue, ligaments, tendons,cartilage and/or bone unless specifically referred to otherwise.

The following discussion includes a description of bone cement mixingapparatus and related methods of employing the apparatus in accordancewith the principles of the present disclosure. Alternate embodiments arealso disclosed. Reference will now be made in detail to the exemplaryembodiments of the present disclosure, which are illustrated in theaccompanying figures. Turning now to FIGS. 1-7, there is illustratedcomponents of a bone cement mixing apparatus 20 in accordance with theprinciples of the present disclosure.

The components of bone cement mixing apparatus 20 can be fabricated frombiologically acceptable materials suitable for medical applications,including metals, synthetic polymers, ceramics and bone material and/ortheir composites, depending on the particular application and/orpreference of a medical practitioner. For example, the components ofbone cement mixing system 20, individually or collectively, can befabricated from materials such as stainless steel alloys, commerciallypure titanium, titanium alloys, Grade 5 titanium, super-elastic titaniumalloys, cobalt-chrome alloys, stainless steel alloys, superelasticmetallic alloys (e.g., Nitinol, super elasto-plastic metals, such as GUMMETAL® manufactured by Toyota Material Incorporated of Japan), ceramicsand composites thereof such as calcium phosphate (e.g., SKELITE™manufactured by Biologix Inc.), thermoplastics such aspolyaryletherketone (PAEK) including polyetheretherketone (PEEK),polyetherketoneketone (PEKK) and polyetherketone (PEK), carbon-PEEKcomposites, PEEK-BaSO₄ polymeric rubbers, polyethylene terephthalate(PET), fabric, silicone, polyurethane, silicone-polyurethane copolymers,polymeric rubbers, polyolefin rubbers, hydrogels, semi-rigid and rigidmaterials, elastomers, rubbers, thermoplastic elastomers, thermosetelastomers, elastomeric composites, rigid polymers includingpolyphenylene, polyamide, polyimide, polyetherimide, polyethylene,epoxy, bone material including autograft, allograft, xenograft ortransgenic cortical and/or corticocancellous bone, and tissue growth ordifferentiation factors, partially resorbable materials, such as, forexample, composites of metals and calcium-based ceramics, composites ofPEEK and calcium based ceramics, composites of PEEK with resorbablepolymers, totally resorbable materials, such as, for example, calciumbased ceramics such as calcium phosphate, tri-calcium phosphate (TCP),hydroxyapatite (HA)-TCP, calcium sulfate, or other resorbable polymerssuch as polyaetide, polyglyclolide, polytyrosine carbonate,polycaroplaetohe and their combinations. Various components of bonecement mixing system 20 may have material composites, including theabove materials, to achieve various desired characteristics such asstrength, rigidity, elasticity, compliance, biomechanical performance,durability and radiolucency or imaging preference. The components ofbone cement mixing system 20, individually or collectively, may also befabricated from a heterogeneous material such as a combination of two ormore of the above-described materials. The components of bone cementmixing system 20 may be monolithically formed, integrally connected orinclude fastening elements and/or instruments, as described herein.

In one embodiment, as shown in FIGS. 1-7, a bone cement mixing apparatus20 is provided. Bone cement mixing apparatus 20 includes a mixing vessel22 for mixing first and second materials to make bone cement. The firstand second materials are used to fill bone cavities. Examples of cavityfilling material include: bone cement (e.g., polymethyl methacrylate(PMMA) cement, ceramics); human bone graft (e.g., autograft, allograft);and synthetic derived bone substitutes (e.g., calcium sulfate, calciumphosphate, hydroxyapatite). Cavity filling materials can be supplementedwith other therapeutic substances, e.g., antibiotics, growth factors andchemotherapeutic agents.

Bone cement mixing apparatus 20 includes a mixing vessel 22 having aninner surface 24 and an outer surface 26. Outer surface 26 extendsbetween a first end 32 and a second end 34. Inner surface 24 forms acavity, such as, for example, a bowl 28 for disposal and mixing of firstand second materials. It is contemplated that mixing vessel 28 be round,oval, oblong, square, rectangular, polygonal, irregular, uniform,non-uniform, offset, staggered, tapered, consistent or variable,depending on the requirements of a particular application. Inner surface24 includes an orifice 30 disposed at the second end 34. It iscontemplated that orifice 30 be round, oval, oblong, square,rectangular, polygonal, irregular, uniform, non-uniform, offset,staggered, tapered, consistent or variable, depending on therequirements of a particular application.

Bowl 22 includes flanges 76 that extend outward from outer surface 26 ofbowl 22 and transverse to central axis A. Flanges 76 provide a surfacefor applying a force F to advance a plunger 70 into the passageway, asdiscussed below. Flanges 76 include a channel 82 disposed therein.Channel 82 is configured as a track 84 accept disposal of separator 48,as discussed below. Flanges 76 include a coupling portion 86 configuredto removably couple a base 36 discussed below to bowl 22.

A syringe body 52 is attached to second end 34 of bowl 22. Syringe bodyincludes a proximal end 56 and a distal end 58. Syringe body 52 definesa chamber 54 extending between proximal end 56 and distal end 58 along acentral axis A. It is contemplated that syringe body be round, oval,oblong, uniform, or tapered depending on the requirements of aparticular application. Syringe 52 includes a lumen 60 disposed therein.Lumen 60 includes an inner surface 61. Lumen 60 extends through syringebody 52 from proximal end 56 to the oppositely disposed distal end 58along axis A. Proximal end 56 includes an opening 66. Distal endincludes 58 an opening 68. Openings 66 and 68 align with orifice 30 toprovide a passageway between bowl 22 and lumen 60.

Distal end 56 further includes a coupling portion 78 adapted to attachto at least one dispensing structure 80. It is contemplated thatdispensing structure 80 can be a cannula, a needle, a cannulated needleor a syringe needle. Second end 58 includes a coupling portion, notshown, for attachment and detachment of bowl 22. This allows for use ofmore then one or various sized syringe bodies or multiple bowls.

To allow for movement of the bone cement between bowl 22 and syringebody 52 a separator 48 is disposed between bowl 22 and syringe body 52.Separator 48 slides along track 84 disposed in channel 82. Movement ofseparator 48 allows separator to move from a first position to a secondposition along track 84. Separator 48 includes an orifice 50 that alignswith orifice 30 and passageway in its first position. Separator 48 isconfigured to slide between proximal end 56 of the syringe body 52 andbowl 22 from a first position wherein orifice 50 substantially alignswith orifice 30 to a second position wherein orifice 50 is misalignedwith orifice 30 such that separator 48 blocks the passageway betweenbowl 22 and syringe body 52. It is contemplated that separator 48 berectangular, round, oval, oblong, square, polygonal, irregular, uniform,non-uniform, offset, staggered, tapered, consistent or variable,depending on the requirements of a particular application.

To facilitate movement of the bone cement through the passageway, aplunger 70 is provided. Plunger 70 is configured to push the bone cementinto and through lumen 60. Plunger 70 includes a proximal end 71 and adistal end 73. Distal end 71 is configured as a curved or radiusedbutton or knob. Proximal end 73 of plunger 70 includes a handle 72.Plunger 70 is configured to fit through orifices 50 and 30 and slidablyengages and extends through lumen 60 in syringe body 52 along centralaxis A towards distal end 58 of syringe body. Plunger 70 is sized forfrictional engagement with inner surface 61 of lumen 60. Handle 72includes a flat surface 88 that facilitates apparatus resting on asurface of a table. It is contemplated that flat surface 88 berectangular, round, oval, oblong, square, polygonal, irregular, uniform,non-uniform, offset, staggered, tapered, consistent or variable,depending on the requirements of a particular application. Bone cementcan be highly viscous and therefore requiring a significant force to bepushed into syringe body 52. After plunger 70 is inserted into orifices50 and 30, apparatus 20 can be flipped over to rest on handle 72. Byapplying a downward force F on flanges 76, plunger 70 pushes the bonecement through lumen 60 into dispense 80.

To assist in holding apparatus 20 and for the protection of syringe body52 a base 36 is attached to bowl 22. Base 36 extends between a first end42 and a second end 44. Base 36 includes an inner surface 38 and anouter surface 40. It is contemplated that base 36 be round, oval,oblong, square, rectangular, polygonal, irregular, uniform, non-uniform,offset, staggered, tapered, consistent or variable, depending on therequirements of a particular application. Inner surface 38 defines acavity 46 configured for disposal of syringe body 52. Base 36 isprovided to allow the apparatus to stand upright on a surface withoutthe end of the syringe body 52 touching the surface. Base 36 includes anopening 37 for viewing the syringe body 52 therein. In one embodiment,flanges 76 include a coupling portion 77 for attachment of base 36.

For mixing the bone cement materials, a detachable spatula 74 isprovided. Spatula 74 can be detachably attached to base 36, mixingvessel 22 or other surface where practical.

In one embodiment, one or all of the components of the bone cementmixing apparatus are presented in a kit, such as for example, adisposable, peel-pack, pre-packed sterile devices. The kit can also beprovided in a sterilized or in the alternative be provided in asterilizable packaging. The kit includes, at least one of the following:syringe body, mixing vessel, separator, plunger, base and dispensingstructures. The syringes and dispensing structures can be of varioussizes, gauges and types depending on the particular application. One orall of the components of the bone cement mixing apparatus may bereusable and steralizable. The bone mixing apparatus may be configuredas a kit with multiple sized and configured components.

In operation, bowl 22 is attached to syringe body 52. Separator 48 ismoved to its second position, where orifice 50 is misaligned withorifice 30 of mixing vessel 22. Base 36 can be attached to provide aneasier gripping surface for holding apparatus 20. Bone cement materialsare place inside bowl 22 and are mixed thoroughly with spatula 74. Theapproximate time of mixing is about 30 seconds. Once bone cementmaterials are thoroughly mixed, separator 48 is shifted to the firstposition where orifice 50 is aligned with orifice 30. Spatula 74 is usedto push and guide bone cement mixture into syringe body 52. Time forthis step is approximately 20-30 seconds. Plunger 70 is placed intosyringe body 52 through orifices 50 and 30. Plunger 70 is pushed untilthe bone cement is close to opening 66. Apparatus 20 is flipped over sothat handle 72 rests on table or other surface. If base 36 was attached,it can now be removed. A dispensing structure 80 is attached to proximalend 56 or syringe body 52. Apparatus 20 is now resting on handle 72 anda force Fl can be applied to flanges 76 to push bone cement materialinto dispensing structure 80. A plurality of dispensing structures 80can be filled one after another as needed for the particular use.Apparatus 20 provides for quick transfer of the bone cement from bowl 22to dispensing structure 80 thereby allowing for efficient use of timeand bone cement. The present apparatus removes the step of having topour the bone cement into the syringe body. The pouring of the cementallows for spills and wasted cement as well inefficient use of time. Theinitial dose of bone cement into dispensing structure can be discardedas it may contain air bubbles.

It will be understood that various modifications may be made to theembodiments disclosed herein. Therefore, the above description shouldnot be construed as limiting, but merely as exemplification of thevarious embodiments. Those skilled in the art will envision othermodifications within the scope and spirit of the claims appended hereto.

1-20. (canceled)
 21. A bone cement mixing apparatus comprising: a mixingvessel comprising a body defining a cavity, the body comprising oppositefirst and second openings that are in communication with the cavity, themixing vessel comprising a recessed track extending into an outersurface thereof; a syringe body comprising opposite proximal and distalends, the syringe body being attached to the mixing vessel, the syringebody comprising a lumen and opposite first and second openings that arein communication with the lumen; and a separator slidably positioned inthe track, the separator comprising an orifice, the separator beingconfigured to slide between a first position wherein the orificesubstantially aligns with the openings to a second position wherein theorifice is misaligned with the openings so as to block a passagewaybetween the mixing vessel and the lumen.
 22. An apparatus as recited inclaim 21, further comprising a plunger that extends through the openingsof the mixing vessel and into the lumen.
 23. An apparatus as recited inclaim 21, further comprising a plunger that extends through the openingsof the mixing vessel and into the lumen, the plunger comprising a distalend having a maximum diameter that is less than that of the lumen. 24.An apparatus as recited in claim 21, wherein the openings of the syringebody are concentric.
 25. An apparatus as recited in claim 21, wherein:the syringe body extends along a longitudinal axis between the proximaland distal ends; and the separator is configured to slide in oppositefirst and second directions along a transverse axis that extendsperpendicular to the longitudinal axis.
 26. An apparatus as recited inclaim 21, wherein: the syringe body extends along a longitudinal axisbetween the proximal and distal ends; and the orifice is coaxial withthe longitudinal axis when the separator is in the first position andthe orifice is offset from the longitudinal axis when the separator isin the second position.
 27. An apparatus as recited in claim 21, whereinside surfaces of the separator engage side surfaces of the track toprevent the separator from rotating relative to the mixing vessel. 28.An apparatus as recited in claim 21, wherein the separator is positionedbetween the openings of the mixing vessel and the openings of thesyringe body when the separator is in the second position.
 29. Anapparatus as recited in claim 21, wherein the orifice is round.
 30. Anapparatus as recited in claim 21, wherein the orifice has a uniformradius of curvature.
 31. A bone cement mixing apparatus comprising: amixing vessel comprising a body defining a cavity, the body comprisingopposite first and second openings that are in communication with thecavity, the mixing vessel comprising opposite first and second flangesthat extend outwardly from the body, the flanges each comprising arecessed track extending into an outer surface thereof; a syringe bodycomprising opposite proximal and distal ends, the syringe body beingattached to the mixing vessel, the syringe body comprising a lumen andopposite first and second openings that are in communication with thelumen; and a separator slidably positioned in the tracks, the separatorcomprising an orifice, the separator being configured to slide between afirst position wherein the orifice substantially aligns with theopenings to a second position wherein the orifice is misaligned with theopenings so as to block a passageway between the mixing vessel and thelumen.
 32. An apparatus as recited in claim 31, wherein end surfaces ofthe separator are flush with end surfaces of the flanges when theseparator is in the first position and the end surfaces of the separatorare spaced apart from the end surfaces of the flanges when the separatoris in the second position.
 33. An apparatus as recited in claim 31,wherein: the syringe body extends along a longitudinal axis between theproximal and distal ends; and the tracks extend along a transverse axisthat is perpendicular to the longitudinal axis.
 34. An apparatus asrecited in claim 31, further comprising a plunger that extends throughthe openings of the mixing vessel and into the lumen such that theplunger is movably positioned within the lumen.
 35. An apparatus asrecited in claim 31, wherein the openings of the syringe body areconcentric.
 36. An apparatus as recited in claim 31, wherein: thesyringe body extends along a longitudinal axis between the proximal anddistal ends; and the separator is configured to slide in opposite firstand second directions along a transverse axis that extends perpendicularto the longitudinal axis.
 37. An apparatus as recited in claim 31,wherein: the syringe body extends along a longitudinal axis between theproximal and distal ends; and the orifice is coaxial with thelongitudinal axis when the separator is in the first position and theorifice is offset from the longitudinal axis when the separator is inthe second position.
 38. An apparatus as recited in claim 31, whereinside surfaces of the separator engage side surfaces of the track toprevent the separator from rotating relative to the mixing vessel. 39.An apparatus as recited in claim 31, wherein the orifice is circular.40. A bone cement mixing apparatus comprising: a mixing vesselcomprising a body defining a cavity, the body comprising opposite firstand second openings that are in communication with the cavity, themixing vessel comprising opposite first and second flanges that extendoutwardly from the body, the flanges each comprising a recessed trackextending into an outer surface thereof; a syringe body comprisingopposite proximal and distal ends, the syringe body being attached tothe mixing vessel, the syringe body comprising a lumen and oppositefirst and second openings that are in communication with the lumen; aseparator slidably positioned in the tracks, the separator comprising acircular orifice, the separator being configured to slide between afirst position wherein the orifice substantially aligns with theopenings to a second position wherein the orifice is misaligned with theopenings so as to block a passageway between the mixing vessel and thelumen; and a plunger that extends through the openings of the mixingvessel and into the lumen such that the plunger is movably positionedwithin the lumen.